Our research goals for the coming year are: (A) To characterize malic dehydrogenase, which will be necessary to construct a transitional model of TCA and amino acid metabolism; (B) To finish characterizing pyrimidine nucleoside phosphorylase, to examine the constraints in the model of the mechanism of this reaction; (C) To finish a review with Pat Kelly entitled "Kinetic Models of Metabolism in Intact Cells, Tissues, Organs and Organisms."